Process for enhancing the octane number of naphthas boiling within the gasoline range



Feb. 16, 1960 w. G. ANNABLE Erm. 2,925,373 PROCESS FOR ENHANCING THE OCTANE NUMBER OF NAPHTHAS BOILING WITHIN THE GASOLINE RANGE 3 Sheets-Sheet 1 Filed April 12, 1957 AT TORNE Y Feb. 16, 1960 w, G, ANNABLE ETAL 2,925,373

PROCESS FOR ENHANCING THE OCTANE NUMBER 0F NAPHTHAS BOILING WITHIN THE GASOLINE RANGE Filed April 12, 1957 3 Sheets-Sheet 2 WELDON G. ANNABLE BY WILLIAM L. JACOBS ATTORNEY Feb. 16, 1960 w, G. ANNABLE EI'AL PROCESS FOR ENHANCING THE OCTANE NUMBER 0F NAPHTHAS BOILING WITHIN THE GASOLINE RANGE 5 Sheets-Sheet 5 Filed April l2, 1957 OO. mm

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Omi I.:

oNuva amino INVENTORS WELDON G. ANNABLE WILLIAM L. JACOBS M l y ATTORNEY ".kIn one embodiment oftlie'-inyention'the cracked'rgasof' line'v'cut 'isfsen't by line 17 to"secondary'fractionatorjlS United States Patent` 1 VPROCESS/F0111 ENHANCING ocrANE BER oF NAPnTnAs Bonino GAS- s f Y Y f, invention.

,o LlNE RANGE: .j

2,925,373 llefeefed Feb-16 1969.

lCe

u 'operationr the hydrogenationtakingfplace vzlfjis carried outin a ,guard casey prior to the reforming Step.. The light;y untreated; crakedjfraction in line-19,11

Y is; blended the hydrogenated-,Iefcrmed product jin.

' rystal Lake, lll.;assigner-srtoTliePurevoilrCompany,

Application Anl'gizgiaensfiiiizofeszisf Y The present invention"relates generally to a process for thepreparation 0f hijg'h-octanelnumber .gasolines and,

more-particularly, .to the upgradingpof thermally` cracked gasoline.`

' lCrakingvprocesses have been; the primarysource'sof materials k for producing finished gasolines of :high octane number. g Such gasolines are in demand today for Yhigheomprerssion, internal combustion' Vengines coupled' with linek 24 to form; thel upgraded highoctane :fuel of 'In accordance with alternate embodiment olfinvention. .the debutanizsdgthermallysrasked easolineV I fraction from line 15' is :passed vialin'e 'zrtohydrogena tion unit 26'. I'he hydrbgenated'product passes via line j 27 to secondary fractionat'r' 28.` `A1lightfrctio1`hvinga boiling range-of about 100? to 185 F. with anendpoint no higher rthan about 200 F. is removed vialine 29 and a heavy fraction boilingffrom about-200- AF.V to

aboutA 375 F. with anend-point `'no higher'than'about;

400 F. is removedas bottor'nsljat line 150i' The 'heavy' fraction is sent to catalytic reformer 31 and the reformed products in line 32, when blendedfwith thelight 'fraction in line 29, form vthe upgraded hghloctaiffuelof automatic transmissions. iAlthough the importance' of thermal cracking has diminished asa means ofY obtain-` ing finished gasolines of highf .octane rating, thermal cracking stillremains-as a potentialexpedient for procl essing light recycle stocl'c'randV gas oils of virgin or blended origin. This invention relates broadly to a firmness for 1 upgrading thermally cracked*gsolinesby'seprating such gasolines into a light and heavy fraction, hydrogenating and catalytically reforming the heavy fraction, landrblend-Vv f f ing the resultant catalytica'llyireformedwheavyjfraetion 1 with the untreated light fraction. Y Y

The invention is furtherillustrated by the drawings inwhich: I f

ing the sequence ofsteps involved;-` .4 2;

' Figure'Z is a'graphl showing the' o'ctane-yieldrrelationl ship for the: catalytic 'reforming' ofthe'hydrogenated l heavy fractionof thermally cracked gasoline .compared with -t-hat for'reforniing'a virgin naphtha having'a similar boiling range. Y

`Figure 3 is a graph showing the yield of iin'isl'edgasoline'ver'sus octane rating when upgrading debutanized,

c 375f`F'. end-point, thermally cracked gasoline by blend in gtheY light fraction withfthecatalytically reformed, hy-

drogenated heavy fraction. v o Referring to Figure 1,the general steps of the 'process of'thenvention maybe-followed.- A` gas-oil feed stock,

from 'a source' not shown; is'introdurcecl` through line 10 into af conyentional'thermal cracking'T process, 11. The

crackedproducts" therefrompass ,via line 12 to primary fractiohato'r 13 'Wherein'the C.; andlighter hydrocarbons arespar'ated andwpassfoif via .line "14,' the Vunstabilized .crackedlegasoline"cutlhaving: 'ani of about-f 37 5 F. is' takenlfoi at line?, n

about"375FL aretaken elias/bottoms? at' line 16for rel f and:i fthe`v products boiling above 4cycle` toV thermal cracking processi 11'. 'f The'feed stoek entering' line 0V 'may 'contain fr 50-60%i offrecycle wherein'a light vfraction having a boilingr-angeof. about 100v to 185 F., `with an end-pointno higher-than about 200V is removed 'atline 19 and a heavy fraction boil#y o as -Figure 1` is a generalilow diagram zoflheprocess showthis invention. Y

The invention therefore has .asn itsprimay object a o l process for upgrading'thermallyicracked; easglinesf 1 Another `object is toprovide anintegrated; split .treatlmentrof a thermally cracked gasolineoriractionsthere- Vof to produce a high-octanergasoline. f

y Still k 'another object' of the@'inverlrtio'rl;-A is to'jprovide an integrated split treatment,--hydrogenationandiatalytic reforming process for thermally'jeragked"gasoline or fractions'thereof to produce a -hig'h-foctane gm olinev having a minimum increase invsensitiyity.yV "1A-'ff A further object of the invention--isjto*proyidea processfor upgrading thermallyjc'rafcked gasoline byjfractionating the '375 F. end-pointgasoline into a light and 'heavy fraction,Y catalytically eforming-the ,heavyiracf tion, and blending the v'catalytically reformed heavy frac# tion .withl the untreated light flfractionlt'obtain a high l octane' product. Y.

.Another Object of the invetiO is t0. lengte@ cracked t gasoline with a minimum increase; sensitivity by mildly, hydrogenating4 375 end-point, thermally cracked gasoline ina separate hydrogenationunit prior to fractionating it into light and Yheavy fractions',l catalytically reforming the heavy fraction andblending the reformed heavy fraction with the hydogenated light fraction to obtain a highfoctanejproduct. n

It is generallymknownv that there isVY a dierencebetweenthe F-lor re'searchoc'tane'numbe (CRC'designation PLI-545) and the F-Z or motor octane numberY (CRC designation PL2-545) of sparkgnitedfuels for internal combustion engines. 'The apparent difference' between these valuesas act11ally-found-in-blend testing;

' or theV so-calle'd sensitivity ifactor,is,used hereinas an expression of the road performance characteristics of the finished products to lgive a Ymore're'alistie approach.' The increase in sensitivity of gaSOlinetype.zniotorfnels isprima'rily due to the factthat .refining techniques generally employed to process crude oil fractionsgsuch as .fcracking and reforming, 'are ratherlimited v'in their ability V to' .,produce gasoline'of high=1=`12 anti-knockrquality.

ing-from about 200.,F. to about 375 "F.,'with 'an 'end-Y pointno higher than about 400 IF.y is removed at lline 20. The heavy fraction ishydroge'nate'd in unit 211nder mild conditions to saturate theolefins and to eiectde-v sulfrization. The hydrogenatedproduct proceeds, with or-'without further treatment, directlyinto catalytic-re- I forminglunit 22 vialine vZ3. vvIn a 'commercial'reformlA stock having the followingl composition and'general'chab' l acteristics was used:

To 'more specically illustrjatethe' invention,l ait-feed checkers Thefeed stock shown in Table I Was treated to thermal cracking at about 900 to 1G00 F., 400-600 p.s.i.g. to produce wa thermally cracked 431 end-point gasoline. This xproduct Wasdebutanizetl tor'erve about 7.44 vol. peifciitof C4 hydrocarbons Vand lighter, and then was fractionated into alight and heavyfraction. The propcities 'of the thermally cracked stock andthe light and hilry fractions produced ltherefrom are shown in Table I.

TABLE II light -and heavy fractions of thermally iiispctin data for Cracked gasoline l. g y Thermally Light YHeavy Fraction Cracked Fraction Fraction Gasoline Vol.` Percent' bf `Debutanized .,'Ihermally Cracked Gasoline 28.8 71. 2 Gravity, API 79. 3 45. 8 ASTMDistillat 1 IBP- 98 Y 99 210 5%- 113 108 226 l% 125 110 238 20% 151 112 251 30% l185 115 263 40%'. 219 118 281 50%- 253 122 301 60%1 285 126 324 .70%- 319 132 348 V80% 352 140 370 90%- 388V 150 393 95%- 412- 156 409 DP- 161 EP. 431` 162 436 Rec- 98.0 98.0 99.0 Res- 1.1 0.6 1.0 YLoss 0.9 1. 4 o. o Refractive Indexfn `/D 1. 4238 1. 3802 1.4478 Vol. Percent Naphthenes and Paraiflns 50. 1 46. 4 41. 2 Vol. Percent Oleiins.` 33. 7 52.3 31. 4 Vol,A Percent Aromat1cs 16. 2 1.3 27. 4 Total Sulfur, Wt. Percen 0. 038 0.007 1 0.042 Research Octane, clear 77. 0 85.2 71.2 y:i-L() TEL, 85. 6 93.0 +3. ml. TEL 90.0` 96.0l 84.8 Motor Octane, clea 70.0 76. 1 65.0 +1.0 ml. TEL 76. 4 81.9 80. 9 84. 6 77. 5

The light Aand heavy fractions were divided into several portions. OneY portion of leach of the light and heavy fractions was subjected to hydrogenation under the operating conditions and Ymaterial balance data shown in Table I IVI, using Filtrol R-3241 catalyst which comprises 9% molybdenum oxide on alumina.

TABLE 'III Hydgnation l0) light and heavy fractions 0f thermally y cracked gasoline g OPERATING CONDITIONS AND RESULTS Run Y HT-77, -78 PIT-80, 81 K Y and 79 and 82 Fraction Light Heavy I Fraction Fraction Operating Conditions:

' Temperatures, F.:

grlehater 600 644 0C 600. G50 P. Cat. Bed? 674 743 ressure, p.s.1.g 500 LVHSV". 2. 4 Y Hzrate, Ftlbbl. (STP 2048 2177 Material Balance, lPercent 99.2 100.1 No-Loss Liquid Recovery:

Wt. Percent o Liq. Charge 100. 4 100. 6 Vol. Percent of Liq. Charge 102. 2 101. 7 Inspection data for Hydrogena Prdncts: o API Yravl y,V g Y 83.2 ASTM Distillation, F 47 7 `IB]? 98 209 5%--.- 106 228 10%.-- 110 238 113 250 sola-- 116 266 401%.- '117 283 50%.-- 123 304 60%.-- `127 326 70% V132 ,348 80.` n 141 370 90% 153 393 4 TABLE` nr-continued Run EIT-77, 78 ZEIT-80, 81

and 79 and 82 Fraction Light Heavy Fraction Fraction Inspectionl data ior Hydrogenated Liquid K' t' VProducts;Continued p Y i ASTM Distillation, FContinued a f les ..166 ',445 l -9 8. 0 .99. 0 0:5 1.0 "1.5 0.0 1. 3705 1. 4401 99.0 76. 5 'V01 Percent Oleiins 0.2 0.5 Vol. Percent Aromatics. 0.8 23.0 Total Sulfur, Wt. Percent 0.004 0. 03 Research Octane clear 68.0 54.0

+1. m1. TEL so. 2 -|30 ml. TEL 89.1 Motor Octane, clear ,66, 2 +1.0 ml. TEL 81.8 +3.0 ml. TEL. 84. 9

In order to demonstrate the eiiect of the hydrogenation process on the sensitivity before further processing, the octane numbers of various blends of untreated and hydrogenated light and heavy fractions Were'determined. The results are shown in'Table IV.

Effect of hydrogenati'on on blends of light antiv heavy fractions 'of thermally cracked gasoline Composition ]3lend1\lo Y 1 y 2 3 4 Materials: Untrcated Light Fraction Untreated Heavy Fraction. Hydrogenatcd light fraction Hydrogenated heavy fraction.

Vol. percent oi thermally cracked gasoline The results in Table IV show that hydrogenatin'g-Yall or part of thermally, cracked gasoline decreases its 'octane rating and reduces its sensitivity. However, when the hydrogenated heavy fraction is subsequently catalytically reformed, a high-octane product is obtained,V

rIn order to demonstrate the effect of catalytically reforming the hydrogenated heavy fraction of the cracked gasoline, a series of experimentswere carried out with threecomparative runs conducted at reactor inlettemf vperatures of 900 F., 950 F. and`1000 F. usinga desulfurized virgin naphtha and a `portion of the ,hydrogenated, heavy, cracked gasoline described inq'IableuIrII. TableV V givesrthe operating conditions and Vresultsof these experiments which were conducted in they presence of a platinum catalyst. v y

Referring to Table V, iti is Ypointed oututhatj the liquid product from the mild hydrogenation of the heavy frac: tion of the cracked 'gasoline Was fractionated to Vrecover 83.9 vol. percent overhead material before the experiments were conducted. This overhead material had a Vboiling range similar to thatcf the desulfurized virgin v`naptha which was used for comparison. Inspection data forthe liquid products obtained in kthe experiments indicated by Table V are shown in Table VI. 'Ilhese indicate that less hydrocracking occurs .when reforming the hydrogenated heavy fraction of 'the cracked gasoline than is evidenced in reforming the desulfurized virgin naphtha. Analysis of the 'productfgas for these experiments was found 'to Csubstantiate this inlirlg,V Also, theoverall acca-are hydrogen'a'ted heavy'fractiomeo thermally cracked 1 gasoline .i Y Y I OPERATING OONDITIoNs AND REsUI/Ifs Charge Stock..'..-- lDesulfurized Virgin Naphtha v20G-400" F. Hydrogenated Heavy Fractions of Cracked Y Gasoline. Operating Conditions: i

'Temperatures,'F. i T., Preheater- 904 1954 995 902' Block.-. 1 V893 944 1002 901' :Bed Y I -sss\ 935 84s- Pressure, p.s.i g- 500 500 L SV 1.8l 1.9 k1.a y Bfliate FtJ/bbl. (STP) 2572 I 2755 2478 2803 Material Balance, Percent- 99.3 99.8 Y 97.5 99.1 No Loss Liquid Recovery: ,1

Wt. Percent-of Llq.Charge 92.3 i '82.5 71.4 93.5 .f Vo1.Per cent.ofLiq.-Charge 89.9 '-81.0 08.1 92% product distribution` upon .comparison showedthat less:A Y cracked'gasoline a starting materiaLarealso shownv f hydrocrackingtook place when Y, tl1 e ,20 0-.400 F. boiling Table The data shjow' thatjntliermallyw cracked range, fhydrogenated. heavyfraetionof crackedgasoline 251fgasolinecan be upgraded tov ahigh'octane'levelwithoutl .l

was reformed `as compared with the1rf0mngofthe seriouslosses -in yield. Although various proportionsofdesulfurized Virgin naphtha. These results are shown the light and heavy A.fractions may be used in blending up graphically .in Figure'IvI. 1 the productsprodnced `by thc process of the'inventionftof Catalytic rfqmngof'deslfurized virgin naphtha and;

" hydrogenated fheavyifraction of thermally crack`ed gasoline n v g' -1 INSPECTION DATA Fon LIQUID PRODUCTS p Run i Charge CR-l (JR-2 (3R-3v .Charge CR-4 OR-5 Olii-..

Charge Stock..--. s Desulfuriaed Virgin Naphtha` V20G-.400" F. Hydrogenated Heavyliracf.;A 1

l' v f tion of Cracked Gasoline A,

Gravity, API Y 54.5 50.0 50.9 49.0 v48.2 43.9 ASTM Distilletion,

IBP 210 102 80 102 85 `80 5%- 254 156 108 158 124 l109 263 196 129 186 149 130 273 234 168 217 186 178 280 258 210 232 218 230 288 271 248 245 238 250 296 284 274 259 260 263 304 295 290 274` 278 273 314 308 306 293 '296 289 325 324 322 316 318 .308 s -339 347 361 340 352` 353 349 375 370 EP-. 375 413 424 419 435 485. Ran 99. 5 97. 2 93. 0 97. 9 94. 5 94. 0 Re: 0. 4 1. 4 1. 0 0. 9 1. 3 1. 2 Tnsu 0.1 1.4 6.0 1.2 4.2 4.8k Reid Vapor Pressure. 9. 9 17.0 7. 3 13. 9 16. 7 Refractive Index 11W/D 1. 4230 1. 4390 1. 4410' 1. 4435 1. 4470 1. 4590 Vol. Percent Naphthenes and Parains. k91.8 58.5 Y 43. 4 53.4 43. 6. 25.3 Vol. Percent Olens 1.0 0, 8k 0. 7 0. 7 0.4 0.3' Vol Percent Aromatics.. 7. 2 40. 7r 55. 9 45. 9 56. 0 74. 4 :i Wt. Percent; Total Sulfur.. 0. 009 0. 013 0. 017 0.004 0. 01 0. 01 Vol. Percent 03's and Lighterf 0.6 1.4 1.1 1.8 1.7 l Vol. Percent Gis- 3.2 7. 8 2. 8 6. 6 8.4 Vol. Percent OsandHeavier.' 96.2 90.8 96. 1 91.6 89.9 Molecular Wt. (CHS-.H f y 110 110l 107 101 f 102l Spec. Gravity (Cys-H.. 0. 7860 0. 7972 0. 7914 0.8035 0.827 Research Octane, clear Y 39.0 Y 85.0 98.0 88.7 98.6Y Y Y103.6 Research 0ctane, +3.0,m1. TETI 95.5 102.51 97.9 103.8 108.6 Y v Following these experiments, a -number`of'v:blend s. of 35', prepareinishedgasolines of particularoctane1ley'els;.jit isl the untreatedlight fractionof thermally cracked gasoline I most Vdesirable use Av'all ofeach component-produced (Tablellywith the three products robtained-in the catalytic. Referring-to the-graph, lFigure .lllilthereisshwn Jar i' i reforming of the..200-400fF.' hydrgenated .heavy4 fracplot offthe 'octane'ratings' against Ythe yieldsofl finished:

tion ofthe thermally cracked 'gasoline wereprepared andV gasdlines forfupgradng .the 375?- end-point cracked theirloctanerratings determined; -In addition, blends of 70 gasoline. The curves are'ba'scrd on` blending the-Slight;A the-hydrogenated light fraction of cracked gasoline (Table untreated fraction' of thermally cracked gasoline viiththf III) with -these same reformed-products were prepared catalytically reformed,"200.400 F.; hydrogenated heavy Aand' their octane ratings tested.4` kThe 'results lare shown Yfractionofthe cracked gasoline. According to thevg'raph; in Table VII. y f 4 n 100 research octane`(3.m1; TEL)/gasolinecanbe-produced The yields of finished gasoline, based-on the 2375" F. 15 from 375 end-point cracked gasoline with a 90 -vol--pe'-- @essere TABLE VII Upgrading 375 F. E.P. thermally cracked gasoline octane ratings of blends of finished products A. UNTREATED LIGHT FRACTION AND REFORMED HEAVY FRACTION B. HYDROGENATED LIGHT FRAIION AND REFORMED HEAVY FRACTION +3.() m1. E Sensitivity (Leaded cent yield offnished product. Similar curvescan be shown for the blends prepared using the hydrogenated light fraction.

v The foregoing examples are to be considered as non, limiting and other manipulative techniques may be employed in carrying out the operations of invention; for example, in determining the cut-point for separating the low-boiling fraction and the high-boiling fraction in the initial fractionation, vthe proportion of the wfull-boilingrange gasoline which is to be catalytically reformed Ymay be determined experimentally. The selected low-boiling fraction will be generally characterized by a boiling range of 1D0-185 F. with an end-'point no higher than 200 F. The clear research octane rating should be n85 or higher and the leaded (3 TEL) research octane rating should be 96 or higher. The remaining `material comprises the high-boiling fraction and is generally characterized by a boiling range of D-375 F. with an end-point no higher than 400 F.

'lille feed stocks to which the present invention is applicable comprise gas oils .broadly having initial boiling points of about`400 F. and end-points ranging from about 600-1000f F. These materials may contain portions of cracked cycle `stock and various fractions of virgin gas oil, such as kerosene and diesel cuts. It is recommended that vabout 40 to 50% of the feed stock comprise virgin material.

The general conditions for the thermal cracking step are as follows:

The fractionation step may be carried out in any type of equipment which is capable of separating a low-boiling fraction boiling in vthe rangeof'about: 100 to 185 F., with an ,-.endpoint lnot higher than about 200F., andY a heavy fractionv boiling in the range of about l20010 375 F., with an end-point no higher than about 400 F.v The fractionation is lconducted so that substantially all of the thermally cracked gasolineis recovered in the light and heavy fractions, therev being substantially no heavy ni'aterallremaining. `The smllamountof Cga'nd lighter hydrocarbons are, of course, 'emoved .prior to the .fractionation f V2,750,329 may be used. A preferred -form of catalyst for The hydr'gtin of the heavy fraction is conducted .by the use ofconventional techniques. The operating conditionswhich may be employed vare as follows:

Conditions Range Preferred Temperature, 600:80@ v'1,50 Pressure, p.s.i.g--- 3D0-600 500 LVHSV 1. o-io. 0 2. 5 Hg'rate, ft/bbl. (STP) 1, 50G-75,000, 2,000

suitable carrier suchV assilica-alumina, alumina, silica-A alumina-manganese, kieselguhr, etc.;` examples, witl1- out limitation on the type ofcatalyst, 'may be 'cited'nickeL platinum and copper Vin the form of --chrom-ites, -sultes, etc., and also oxides of nickel, molybdenum, cobalt andr tungsten used singly or in admi-xture.' A preferred catalyst yfor the hydrogenation `step comprises molybdena on alumina, Whichis described in our copending application, Serial Number l593,821, led June-26, 19576.

Similarly, the catalytic reforming operation Whiclifis applied .to the hydrogenated, high-boiling fraction employs customary procedures known to the art. The catalyst for this joperation may be a group VIII noble metal catalyst comprising platinum-rand palladium used alone or deposited upon aj'suitable'inertjcarrier,,preferably one containing silica. VA number of 'catalyst compositions are available and known to the art for use as reforming catalyst. Those catalyst compositions described in U.S. Patents 2,479,109; 2,478,916; 2,550,531; 2,589,189; 'and the reforming is a platinum catalyst containing about 0.2 to 0.6 percent of platinum on a -highly extended aliunina base having a surface area in excess of 350 square rnc-tersper gram. The catalyst may be in an extruded form, or pellets having diameters of about 3/32.

The reforming operating conditions thatimay be used are as follows:

Conditions Range Preferred Temperature, F 900-1,050 1,000 Pressure, p.s.i.g 300-600 500 LVH g l-3 2 H2 rate, ftlbbl. (STP) 1, 50G-5,000 2, 500

" ing fractions may vary V-somewhat lfrom l8f5-200 Where feed hydrocarbons of diierent characteristics are to be treated.

The thermally cracked .gasoline ytobeY 'upgraded may be any Vtype of feed Vhydrocarbon or mixture which 'is amenabletoproducing a good grade of gasol'ineand may be produced by any of the known methods of thermal cracking. The charge stock to the thermal cracking .operation shouldcontain about/'40% to'50% of virgin material with the balance-being recycle 'stock or other extraneous feeds suitable for Iproducing gasoline. The boiling'range of this initial charge stock may be about 350 19900" Ff. or a's high aS 1000;"

The data presented shows that byz means of the in tegrated hydrogenation-fractionation-reformingj Y process or the integrated fractionation-hydrogenation-reforming k process of this invention, the'thermally cracked gasoline can be upgraded to yield on subsequent blending of prod'- ucts a highoctanenumber product with no appreciable increase in sensitivity. The invention is subject to various' thereto appear in the appended claims. K, f

What is claimedis: Y 1. AV process for enhancing the octane number yofa full-boiling-range gasoline produced in the thermal crackyobvious modifications and the only limitations attaching ing of a petroleum gas oil having a total sulfur content'of Y 'notrrrore Vthan about 0.3 weight percent which comprises f fractionating said gasoline to provide a low-boiling frac--V tion having an ASTM end-point of'about ZOOP-F. andra consecutive high-boiling-range fraction, catalytically v hydrogenating said high-boiling fraction at a temperature of about 60C-800 F. at 300-600 `p.s.i.g. ofvhydrogen'using a liquid-volume-hourly-space-velocity between about 1.0

and 10.0 and a hydrogen ow'rate of about 1500 to 5000 cubic feet per barrel of feed at standard temperature and pressure, reformingV saidhydrogenated high-boiling fraction at a temperature of about 900-1050 F., at 300-600 p.s.i.g. of hydrogen using a liquid-volume-hourly-space velocity of about 1.0-3.0 and a hydrogen ow rate of about 1500-5000 cubic feet per barrel of feed at standard temperature and pressure, and blending said reformed high-boiling fraction with said untreated low-boiling frac? tion to provide a ull-boiling-range gasoline.

2. The process in accordance with claim 11i1'1 whichV said thermally cracked Vgasoline hasV the following ap-l proximate physical properties:

Gravity, API l Y ASTM distillation, F., I.B.P.E.P. 98-431 Rerfactive index, n/D 1.4238 Vol. percent naphthenes and parains 50.1 Vol. percent oleiins 33.7 Vol. percent aromatics 16.2 Total sulfur, wt. percent 0.038 Research octane No., clear '..Y..v 77.0 +1.0 m1. TEL 5.-.. V- 85.6 m1..TEL '90.0 Motor octane No., clear V70.0v

+1.0 m1. TEL 76.4 +3.0 ml. TEL 80.9

3. The process in accordance with claim 1v in which the low-boiling fraction has the following approximate physical properties:

Gravity, API Y 79.3 ASTM distillation, F., I.B.P.E.P. 99-162 Refractive index, nm/D 1.3802 Vol. percent naphthenes and parafns 46.4 Vol. percent olens n 52.3 Vol. percent aromatics 1.3 Total sulfur, wt. percent n 0.007 Research octane No., clear .L 85.2 -|1.0 m1. TEL 93.0 +3.() m1. TEL 96.0 Motor octane No., clear `76.1 +1.0 m1. TEL 81.9 +3.() m1. TEL i.--

4. The process in accordance with claim 1 which said 5. The process in accordance with claim 1 nwhich theV following range of physical properties; Gravity, "API Y" v ASTM distillation; I.B.P.E.P 80-485 Refractive index, :12o/D `1.44351.4590 Vol. percent naphthenes and parains 25.353.4

Vol. percent olelins-; 0.3-0.7 Vol. percent aromatics 45.9-74.4 Wt. percent sulfur 0.01 Research octane No., clear y88.7-103.6l Research octane No. +30 ml. TEL 97.9.108.6

i 6A. Theprocess in accordance with claim 1 lin which the total production 'of liquid products from said fractionation, hydrogenation and reforming processes' are blended to form a full-boiling rangeA gasoline having an enhanced octane number. l

7. A process forenhancing the octane number of a full-boiling range gasoline produced in the thermal cracking of a petroleum gas oil having a total sulfur content of not more than about 0.3 weight percent which consists in fractionating said: gasoline to provide a low-boiling fraction having .an ASTM end-point of about 200" l".V

and a total sulfur content 'of about 0.007 weight percent 4and a consecutive Vhigh-boiling-range fraction having an 'ASTM end-point of about 400 F. and a total sulfur content of about 0.042 vweight percent, catalytically hydrogenating said high-boilingr fraction at a temperature of about 600 to 800 F. at 300-600 p.s.i.g. of hydrogen using a liquid-volume-hourly-space velocity of between about 1.0 and 10.0 and a hydrogen iiow rate of about 1500 to Y5000 cubic feet per barrel of feed at standard temperature and pressure to produce a hydrogenated product having a total sulfur content of less than about 0.03 weight percent, reforming said hydrogenated product at a temperature of about 900 to 1050 F. at 300-600 p.s.i.g. of hydrogen using a vliquid-volume-hourly-spatse velocity of about 1.0 to 3.0 and a hydrogen ow rate consecutive high-boilingl fraction :before hydrogenation Y of about 1500-5000 cubic feet per barrel of -feed at standard temperature and pressure, recovering a reformed high-boiling fraction and blending said reformed highboiling fractionwith said untreated low-boiling fraction to produce a full-boiling gasoline of increased octanev number and decreased lead sensitivity.

References Cited in the le of this patent Y A UNITED STATES PATENTS 2,025,255

Taylor Dec. 24, 1935 2,367,527 Ridgway Ian. 16, 1945 2,389,712v Atweu Nov. 21, 1945 2,413,312 t Cole Dec. 31, 1946v 2,463,741 Byrns Mar. 8, 1949 Dickinson June 16, 1953 hydrogenatedv and reformed heavy fraction has-'the 

1. A PROCESS FOR ENHANCING THE OCTANE NUMBER OF A FULL-BOILING RANGE GASOLINE PRODUCED IN THE THERMAL CRACKING OF A PETROLEUM GAS OIL HAVING A TOTAL SULFUR CONTENT OF NOT MORE THAN ABOUT 0.3 WEIGHT PERCENT WHICH COMPRISES FRACTIONATING SAID GASOLINE TO PROVIDE A LOW-BOILING FRACTION HAVING AN ASTM END-POINT OF ABOUT 200* F. AND A CONSECUTIVE HIGH-BOILING-RANGE FRACTION, CATALYTICALLY HYDROGENATING SAID HIGH-BOILING FRACTION AT A TEMPERATURE OF ABOUT 600-800* F. AT 300-600 P.S.I.G. OF HYDROGEN USING A LIQUID-VOLUME-HOURLY-SPACE VELOCITY BETWEEN ABOUT 1.0 AND 10.0 AND A HYDROGEN FLOW RATE OF ABOUT 1500 TO 5000 CUBIC FEET PER BARREL OF FEED AT STANDARD TEMPERATURE AND PRESSURE, REFORMING SAID HYDROGENATED HIGH-BOILING FRACTION AT A TEMPERATURE OF ABOUT 900-1050* F., AT 300-600 P.S.I.G. OF HYDROGEN USING A LIQUID-VOLUME-HOURLY SPACE VELOCITY OF ABOUT 1.0-3.0 AND A HYDROGEN FLOW RATE TO ABOUT 1500-5000 CUBIC FEET PER BARREL OF FEED AT STANDARD TEMPERATURE AND PRESSURE, AND BLENDING SAID REFORMED HIGH-BOILING FRACTION WITH SAID UNTREATED LOW-BOLING FRACTION TO PROVIDE A FULL-BOILING-RANGE-GASOLINE. 